Acid stabilized pasta

ABSTRACT

Acid-stabilized pasta is prepared with at least one polymeric food-acceptable acid.

FIELD OF THE INVENTION

The present invention relates to acid-stabilized pasta and to processesfor its preparation.

BACKGROUND OF THE INVENTION

Pasta is traditionally prepared by formulating a fresh pasta dough, andthen boiling the dough in water to a minimal extent before consumption.As a result, the pasta has an appealingly fresh taste and texture.However, a major drawback of utilizing fresh pasta dough is that it hasa high water content, which supports the growth of detrimentalmicroorganisms, and, therefore, spoils rapidly if not used immediately.The fresh pasta dough is usually meant to be made, purchased and cookedin a short period of time. Often fresh pasta dough is refrigerated as away of prolonging its life. But, even at low storage temperatures, freshpasta dough has a very limited term.

One attempt to remedy the situation has been the provision ofconventional dry pasta such as macaroni, spaghetti and noodlesconsisting basically of dough made with one or more of semolina, farina,or another flour, and water. The pasta is formed by extrusion into avariety of sizes and shapes, and dried to a moisture content of 12% orless to obtain a hard product for storage. At a moisture level of 12% orless, such dry pasta will not readily support the growth of mold, yeastor other spoilage microorganisms. Thus, the pasta, if kept dry, can bestored without refrigeration for long periods of time. However, thedried pasta must be cooked relatively extensively to effectre-hydration, often to the extent that the weight of the rehydratedpasta is, for example, 2.6 times that of its dry weight, and typicallythe rehydrated pasta does not simulate the taste and texture of a freshpasta.

In another attempt, pasta has been precooked and provided in cans,typically with tomato sauce, meat sauce, gravy, meatballs, or the like.Canned pasta-containing products typically are prepared as follows:blanching dried pasta in boiling water to soften and hydrate the pastato a water content of about 65% to 75%; filling the blanched pasta intoa can together with sauce, meat, or the like; sealing the can; andretorting the sealed can under time-temperature conditions sufficient toprovide a sterile product--typically about one hour at 115° C. Since thepasta is hydrated to a water level above 12%, the pasta has a watercontent which will support the growth of spoilage organisms. Therefore,the canned pasta-containing products must be subjected to relativelysevere heat processing conditions in order to produce a sterile product,which is then maintained in the sterile state due to sealing in the can,so as to protect against microorganism-spoilage to make a commerciallyfeasible product. Processing under these severe conditions results in ataste and texture which is less than optimal, and limits theacceptability of canned pasta-containing products.

Pasta is also available in a frozen, raw state which can be freshlyboiled in the home immediately prior to consumption. However, freezingadds considerable expense to the manufacturing and delivery costs of theproducts. Moreover, frozen products are perceived by many consumers tobe less desirable then products prepared directly from a fresh, unfrozendough.

The art has long been searching for a pasta alternative to theforegoing. Such a pasta product should have an extended life at roomtemperature or under normal conditions of refrigeration, be easilyprepared and stored, have substantially no off-flavor in a statesuitable for consumption, be free of surrounding liquid in the storedcondition, and (when in a state suitable for consumption) be at least aspalatable and appear as pleasing as products prepared from conventionaldry pasta.

In past attempts to achieve some of these desired attributes, it hasbeen proposed that pasta could be treated with acid to yield a suitableproduct.

For example, U.S. Pat. No. 4,828,852 apparently relates to a process forthe preparation of precooked pasta which requires boiling pasta inacidified water, soaking a partially cooked pasta in acidified water andcoating the cooked pasta in acidified cream. The acids mentioned includemalic, acetic, fumaric, tartaric, phosphoric and adipic.

U.S. Pat. No. 4,734,291 apparently discloses a process for preparingshelf-stable pasta by partially blanching and hydrating pasta, insertingthe pasta into a container, adding an aqueous acidic solution, sealingthe container and sterilizing the contents of the sealed container.Specific acids mentioned are fumaric, citric, tartaric, malic andlactic.

U.S. Pat. No. 4,659,576 apparently relates to pasta stabilized againstmicrobial decomposition by adding acid to the raw pasta dough beforemaking the pasta. Specific acids mentioned in this patent includeacetic, citric, ascorbic, malic, fumaric, and tartaric.

U.S. Pat. No. 4,597,976 also apparently relates to use of acid in theraw pasta dough. Acids mentioned in this patent include citric, fumaric,lactic, malic, tartaric, sulfuric, hydrochloric and phosphoric acids.

U.S. Pat. Nos. 4,599,238 and 4,552,772 apparently relate to methods forpreparing cooked pasta by boiling the pasta, washing the boiled pastawith water and immersing the boiled pasta in an aqueous solutioncontaining citric acid, lactic acid and table salt, and then packagingand heat- sterilizing the pasta in an aqueous solution.

JP-A-6 307 770 apparently describes the preparation of a noodle whichcontains an acid preservative in its dough. The preservative includes afood-acceptable organic acid, a salt of such an acid and a water-solublemacromolecular polysaccharide or chitosan. The organic acid may becitric, tartaric, malic, fumaric, lactic, acetic or gluconic acid. Thepolysaccharide may be alginic acid or sodium alginate. However, thepolysaccharide appears to be used solely as a texturizing agent. Basedon an analysis of this application, it is believed that the freepolysaccharide is not present as part of the final product since thepolysaccharide appears to be neutralized by the organic acid salt.Moreover, there is no report of stability of the product beyond 10 days.

Thus, it can be seen that there have been many attempts to developacid-treated pasta products which can be stored effectively for anextended period of time. However, these attempts typically involvetreatment with conventional food acids--i.e., generally low molecularweight inorganic or organic acids--and, at least as far as is known,none has resulted in a product with all of the attributes required of apremium pasta product, namely (i) extended life at room temperature ornormally prevailing refrigeration temperatures, (ii) ease of preparationand storage, (iii) freedom from the substantial presence of ambientliquid in the stored condition, (iv) substantially no off-flavor when ina condition suitable for consumption, and (v) when in such condition,palatability and appearance comparable to, or better than, productsprepared from conventional dry pasta. For example, while someconventional acid-treated products may have a somewhat extended storage-or shelf-life, they have an acid taste. Indeed, it would seem to beinevitable that a pasta product treated with acid will have an acidtaste.

Provision of a premium pasta product having the full complement ofadvantageous features described above would be a substantial advanceover the technology discussed heretofore.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the invention to provide a pastaproduct.

It is an additional object of the invention to provide a pasta productwhich has an extended life at room temperature or under normalconditions of refrigeration.

It is another object of the invention to provide a pasta product whichis easily prepared and stored.

It is still another object of the invention to provide a pasta productwhich has substantially no off-flavor.

It is yet another object of the invention to provide a pasta productwhich is free from the substantial presence of ambient liquid in thestored condition.

It is a further object of the invention to provide a pasta productwhich, when in a condition suitable for consumption, is at least aspalatable and appears at least as pleasing as products prepared fromconventional dry pasta.

It is still a further object of the invention to provide a pasta productin a suitable container.

It is yet a further object of the invention to provide a method for thepreparation of the above-mentioned pasta product.

These and other objects of the invention will be readily apparent fromthe following description and claims.

SUMMARY OF THE INVENTION

In one aspect, the invention is a method for the preparation of anacid-stabilized pasta, which comprises treating the pasta with apolymeric food-acceptable acid under conditions such that the pasta'slife is extended without introducing acid flavor notes.

In a second aspect, the invention is a method for the preparation ofacid-stabilized pasta, which comprises treating pasta with at least onepolymeric food-acceptable acid in an amount, for a time, and at atemperature sufficient to effect the pasta's acid-stabilization.

In another aspect, the invention is a method for the preparation ofacid-stabilized precooked pasta, which comprises cooking pasta in anaqueous solution or suspension of at least one polymeric food-acceptableacid, and packaging the precooked pasta in a container.

In yet another aspect, the invention is a method for the preparation ofacid-stabilized pasta, which comprises placing pasta in a container withan aqueous solution or suspension of at least one polymericfood-acceptable acid in an amount such that the water component of thesolution or suspension can be substantially absorbed into the pasta;sealing the container; and heating the container under conditionssufficient for the water component of the solution or suspension to besubstantially absorbed by the pasta.

In still another aspect, the invention is acid-stabilized pasta preparedby any of the methods described above.

In a further aspect, the invention is acid-stabilized pasta which issubstantially free of acid flavor notes.

In yet a further aspect, the invention is acid-stabilized pasta, whichcomprises pasta of water activity greater than 0.5 and a pH below about4.6, and at least one polymeric food-acceptable acid component.

In still a further aspect, the invention is a system, which comprisesacid-stabilized pasta, of water activity greater than 0.5 and a pH belowabout 4.6, at least one polymeric food-acceptable acid component, and acontainer in which the pasta resides.

The pasta in accordance with the present invention is advantageous inthat, unlike previous pasta products, it has the full complement offeatures required of a premium pasta product, in contrast to prior pastaproducts which are deficient in one or more important respects. Forexample, the pasta of the present invention is easily prepared andstored. Further, it has an extended life, and thus lends itself todistribution, display and sale in a wide range of commercial settings,for instance in high-volume supermarkets, in convenience stores and infood-service establishments. Because of the unique attributes of thepresent invention, there is no need to sacrifice the taste and textureof a premium pasta product in order to secure the versatility inadaptation to the different marketing environments described above.

Furthermore, in certain embodiments, the invention is advantageous ineliminating the need for specialized delivery and storage conditionswhich result in considerable cost savings. Unlike fresh and frozenpasta, which must be refrigerated, the precooked pasta of the presentinvention, in these embodiments, can be held at ambient temperature forlong periods of time without damaging the product or affecting itsacceptability. The substantial economies resulting from obviating theneed for refrigeration make the product commercially appealing from acost standpoint.

In other embodiments, the pasta of the present invention can be heldunder refrigeration and will resist microorganism spoilage forsubstantially longer periods of time than are achieved with currentlyavailable conventional refrigerated pasta.

DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS

The acid-stabilized pasta of the invention, and the method of preparingit, provide a product having the attributes of a premium pasta product.It is a preserved food product with enhanced resistance to microorganismspoilage.

Pasta is, generally speaking, a class of food--whether raw, partiallycooked, fully cooked or pretreated in some way--prepared from dough madefrom any suitable material, such as semolina, durum flour, farina,flour, corn, rice or wheat, or any combination of two or more of these,with water. Especially when in the raw or partially cooked state, thepasta typically absorbs water during cooking. It can be made with one ormore optional ingredients, for instance whole egg, egg white, frozen eggwhite, dried egg white, or any two or all of these, seasonings such asonions, celery, garlic and bay leaf, salt, gum gluten and concentratedglyceryl monostesrate. The pasta can be enriched, fortified, etc., as isconventional. The pasta can be in any desired shape, such as sheets,spirals, noodles and tubes. It is within the scope of this inventionthat the pasta be in combination with other food substances such asmeat, cheese, vegetables, fruits, sauces and the like, includingcoloring and flavoring, for example, the pasta in lasagna, filledcapelletti, ravioli or tortellini.

As used herein, the term "acid-stabilized pasta" means pasta treatedwith a suitable acid or acids either in the free or dissociated state,under conditions (e.g., amount of acid, time of treatment, pH oftreatment medium, temperature) such that the number of microbesdestroyed in the pasta is sufficient, at least under conditions ofrefrigeration, to result in the pasta's maintaining its resistance tomicroorganism-spoilage for 90 days or more. Further, as used herein, to"treat" with acid(s) refers to treatment in any way suitable foreffecting intimate contact between the pasta material and the acid(s),for example, by boiling pasta material in acidified water, byincorporating the acid(s) directly in the pasta material duringformulation, by soaking pasta dough in acidified water, some combinationof two or more of those measures, or the like.

In certain embodiments of the invention, the pasta is pre-cooked or atleast cooked partially during preparation for storage and displaypursuant to marketing. In these embodiments, the acid-stabilization ofthe product typically renders it shelf-stable. However, in otherembodiments, the pasta simulates a fresh refrigerated product, and thereis no cooking prior to distribution into marketing channels. The pastain such cases is advantageously refrigerated, and under those conditionsexhibits an extended life vis-a-vis conventional refrigerated pastaproducts.

For purposes of this invention, a product is considered to be"shelf-stable" when that product remains of acceptable quality from thetime of manufacture until the anticipated time of consumption withoutmeans of preservation such as refrigeration. While a shelf-life of even3 or 4 months would be acceptable under certain circumstances,typically, ready-to-eat products are considered to be shelf-stable ifthey remain of acceptable quality for at least 9 months, preferably atleast 12 months, and especially at least 14 months. Sensory attributesof particular interest in assessing shelf-stability are color, texture,aroma, flavor, rancidity and tartness. A product is shelf-stable whenthese attributes are of acceptable quality after passage of the desiredtime. In particular, the growth of spoilage microorganisms should beinhibited in a shelf-stable product and this minimization over longperiods of time is the hallmark of shelf-stability.

By "precooked" is meant that the pasta can be prepared for consumptionmerely by heating it, for instance in a conventional oven or a microwaveoven, or by steaming it or immersing it in hot or boiling water, to adesired temperature for consumption. In a precooking step, the pasta iscooked for a sufficient time such that no prolonged heat treatment willbe necessary in order to complete the cooking for consumption. This stepcan be carried out either in water or in the aqueous solution orsuspension of acid.

Typically, the precooked pasta is reheated for a time of 30 seconds to 3minutes. For example, in certain embodiments the pasta is heated in amicrowave oven for a short time, e.g., about two minutes. In this way,if the pasta is heated in final preparation for dining, so littleheating is necessary that essentially no further cooking occurs.However, in certain advantageous embodiments, since the precooked pastais already fully cooked and ready to eat from the container, it can beused at room-temperature or in a cold pasta salad with no heating.

In still another advantageous embodiment, however, the pasta simulatesfresh, refrigerated pasta and is not fully cooked.

An essential feature of the present invention is the utilization of atleast one polymeric, typically macromolecular, food-acceptable acid.Typically, these acids are of high molecular weight, for example, havinga subunit molecular weight of about 190, and can be copolymericsubstances if desired. Of course, they are non-toxic, and additionallyare materials which have the capability of retarding growth of spoilagemicroorganisms without imparting an acidic or other undesirable "off"flavor to the pasta.

The acid is used in an amount sufficient to attain conditions whichresult in the treated pasta's exhibiting the desired shelf-life orextended life, and one or more other attributes of a premium pastaproduct. It can be appreciated that the precise quantity of acidutilized in any particular embodiment will often depend on otherconsiderations, such as the nature of the final product desired (forexample, refrigerated but not necessarily shelf-stable, ornon-refrigerated and substantially shelf-stable, etc.), the amount andtype of pasta, the pH desired, other substances present, etc. Forexample, when the product is a precooked pasta, the acid can be presentin an amount of from about 0.2 to 2 wt. % of the cooking medium orbrine. However, the quantity can vary from one embodiment to another,and its determination is empirical. For instance, in another embodiment,the acid can be present in an amount as little as 0.085 wt. % of thecooking medium or brine. It is, in any event, within the capability ofone ordinarily skilled in the art, once equipped with the teachings setforth herein, to determine the amount of acid which is needed.

The preferred polymeric food-acceptable acids have a cellulosic orsaccharide-derived backbone with pendent carboxyl groups. A preferredpolymeric acid in accordance with the invention is alginic acid; alsopreferred are the non-alginic polymeric food-acceptable acids such ascarrageenic acid, pectinic acid, carboxymethyl cellulose acid.Combinations of two or more of the foregoing acids can also be utilized.

While the polymeric food-acceptable acid may be introduced as such, itcan alternatively be generated in situ, for instance, by reactionbetween a salt of the polymeric acid and an inorganic acid. Forinstance, alginic acid may be generated by reacting sodium alginate withhydrochloric acid.

Additionally, derivatives of the acid may be used in place of the acid,or derivatives of the acid may be formed during cooking and be presentin the product. All these embodiments are contemplated herein.

That the use of a polymeric food-acceptable acid enables pasta to bemade shelf-stable, and have all the other attributes required of apremium pasta product, is surprising for a number of reasons. Forexample, previously proposed procedures which used an acid have allresulted in products which do not have all the attributes required of apremium pasta product. One typical failing is that the acids used impartan unpalatable acid taste to the pasta. However, this failing isremedied by the present invention.

The suitability of polymeric food-acceptable acids is additionallysurprising since, as far as is known, these acids have never before beensuccessfully used as acidulants for pasta. The aforementioned Japanesepatent application apparently discloses use of polysaccharides, but notas acidulants. Rather, they are believed to be used as texturizingagents, and are not believed to survive processing. Other uses of thepolymeric acids, and their sodium or calcium salts, are as thickeningagents or coatings in food products. Also, alginates have been used asstabilizers in ice cream, water ices, sherbets and cheese, as gellingagents in water dessert gels and milk puddings, as suspending andthickening agents in fruit drinks and beverages, as foam stabilizers inbeer, as emulsifiers in salad dressings and as film forming agents incoatings for meat and fish. For example, U.S. Pat. No. 3,332,786apparently discloses that propylene glycol alginate "stabilizes" starch.(The specific starches mentioned are natural or modified starchesderived from corn, wheat, potatoes, waxy maize and tapioca). However,this stabilization relates to the ability to withstand freeze-thawcycles or gelling problems. It does not relate to, nor was it recognizedas having any ability to providing, shelf-stability or other extensionof product life as discussed herein.

Thus, the prior art provides no suggestion that such polymericfood-acceptable acids could be used as acidulants, let alone with thesurprising results shown by the present invention.

Moreover, these polymeric acids are generally only sparingly soluble inwater. For this reason, it is surprising that they can act as acidulantsat all. It is further unexpected that they can produce the requiredacidification to produce a stable product without the use of undesirablylarge quantities of the acid.

In practicing certain embodiments of the invention, there are twoseparate considerations. The first consideration involves precooking,and the second is pasteurization. While it is preferable to precook andpasteurize simultaneously, it is not necessary to do so. In fact,partial cooking may take place before and/or during pasteurization.

In certain advantageous embodiments of the invention, a pasteurizationstep, sometimes herein referred to as acid-pasteurization, is essential.The minimum requirements are that the center temperature of the foodshould be held for a time sufficient to achieve killing ofmicroorganisms, typically at a minimum of about 85° C. for at leastabout five minutes, and that the food should have a pH less than 4.6. Ifhigher temperatures or lower pHs are used, then the treatment time maybe reduced. However, it is preferred that, as a minimum, thepasteurization step, whatever the pH, should hold a center temperatureof 85° C. for five minutes. More preferably, a center temperature of 93°C., should be held for 10 minutes. Generally, if the pasteurization stepis carried out at a temperature of 100° C. or less, it is not necessaryto use a pressurized heating system. The pasteurization step can becarried out under atmospheric pressure using hot water or steam to heatthe product. If the pasteurization step is carried out at a temperatureabove 100° C., then the use of a pressurized system will prevent waterfrom being driven off. In any event, the pasta is pasteurized while itis maintained at a pH of less than 4.6 by the use of the aqueoussolution or suspension of at least one polymeric food-acceptable acid.

Of course, in other embodiments, it is desired to produce a pastaproduct simulating a fresh product. This can be achieved, for example,by incorporating the acid in the pasta dough or soaking or cooking thedough in an aqueous solution or suspension of acid to effect a pasta-pHlow enough to result in the pasta's maintaining its resistance tomicroorganism spoilage for 90 days or more. For these embodiments, thepH of the product can be less than about 4.6, but can alternatively behigher, for example as high as 6.0, if the product is refrigerated orsome analogous preservative measure is taken. It is within the skill ofthe art to derive the parameters best suited to this situation. Forexample, a higher pH could be employed if the life of the pasta need notbe greatly extended. In these embodiments, too, the pasta typically isalso pasteurized by passing it through a steam tunnel so that its centertemperature is held at about 95° C. for about 5 minutes.

In certain advantageous embodiments, one or more conventional acidulantsis utilized in addition to the polymeric acid. The conventionalacidulants will be used to assist in controlling the pH of the pasta atthe desired level. Typically, the conventional acidulant is present in abrine for cooking the pasta, in an amount of from about 0.1%, or in thepasta in an amount of about 0.05%. However, in some embodiments, theconventional acidulant is incorporated in the pasta dough. In certainembodiments, the conventional acidulant replaces some of the polymericfood-acceptable acid which would otherwise be needed. However, it shouldbe ensured that the amount of conventional acidulant used is not solarge as to impart an unacceptable flavor to the pasta, and that theamount of polymeric food-acceptable acid is not decreased to the extentthat the advantages of the invention are lost.

Suitable conventional acidulants include inorganic acids, such asphosphoric, sulfuric and hydrochloric acids, and organic acids, such ascitric, malic, acetic, fumaric, tartaric, adipic, lactic, ascorbic,sorbic, propionic and erythrobic acids. Citric acid is especiallypreferred, but malic acid is also preferred, as well as ascorbic acid.In certain embodiments, combinations of 20-60 wt. % alginic acid and40-80 wt. % malic acid are used. Examples of combinations within thisrange are 50 wt. % alginic acid and 50 wt. % malic acid, and 30 wt. %alginic acid and 70 wt. % malic acid.

Salt and/or sugar, and other flavorings, for example at about 1 to 2%each, can also be used in the cooking medium or brine.

To measure the pH of the pasta, a known amount of the pasta, for examplea 100 gram sample, is combined with an equivalent weight of distilledwater in a blender until a homogeneous paste is achieved. Electrode tipsare immersed in the paste while the paste is stirred. The electrode isallowed to stabilize for one minute before the pH reading is taken.

As previously discussed, in accordance with certain embodiments of theinvention, pasta is precooked typically by boiling it to bring it to thedesired state of preparation. However, boiling is not necessary and thepasta may be precooked at temperatures below 100° C. In certainembodiments, the temperature is between 90° C. and 100° C., preferablyabout 95° C. When it is expected that significant heat-exposure will benecessary in subsequent processing steps, such as pasteurization orother stabilization, the extent of prior partial cooking--e.g., cookingtime and/or temperature--is commensurately less. Typically, the pasta isprecooked (including any pasteurization or other stabilization) forabout 5-20 minutes, especially 7-16 minutes,--and in certain otherembodiments for about 10-30 minutes, preferably 15 minutes--for instanceby boiling in the aqueous solution or suspension of said at least onepolymeric food-acceptable acid. The aqueous solution or suspensiontypically has a pH from about 2.0-4.0, especially 2.4-2.8. In someembodiments, the aqueous solution or suspension has a pH from about3.0-4.0 , and preferably about 3.5. However, the exact time, pH,temperature and other conditions of precooking can vary from oneembodiment to another, and the skilled artisan will be able to derivethe particular precooking parameters best suited to the situationempirically, based on his level of skill and the teachings set forthherein. For example, it will be appreciated that the cooking times ofthe pasta will vary depending on the size, thickness and shape of thepasta and the degree to which it is precooked. Further guidanceregarding suitable conditions to be used can be obtained from a study ofthe examples set forth hereinafter. Given the above disclosure and theexamples, one skilled in the art will be able to determine appropriateconditions for processing pasta.

After cooking, the pH of the pasta should be below about 4.6 for aproduct whose pasteurization is desired. This is the generallyrecognized maximum pH which ensures that the pasteurized product remainsshelf-stable. Typically, the pH of the pasta is in the range of about3.8 to 4.6, preferably 3.8 to 4.2, or in some embodiments, 4.1 to 4.6,especially 4.3 to 4.4. In one preferred embodiment, the pH of the pastais about 4.0. The pH can be below 3.8. However, the lower the pH, themore acid must be used and the more difficult it is to avoid acid flavorin the pasta. As a practical matter, the skilled person given theinstant disclosure will be able to balance the pH level and amount ofacid used to ensure that the pasta is shelf-stable and has substantiallyno acid flavor notes.

The pasta of the present invention is typically packaged in a containerof configuration, construction and constituent material such that it iscapable of maintaining the acid-stabilized pasta--i.e., providing anenvironment in which the pasta's shelf-stability or extended life due toacid-stabilization is not appreciably diminished by extraneousinfluences for substantially the entire period of its shelf-stability orextended life. During packaging, the temperature of the pasta in certainembodiments remains above about 90° C. while it is being placed in thecontainer. In other embodiments, the pasta can first be cooled. Thepackage is advantageously a container made of amicroorganism-impermeable and/or waterproof material, for example glass,foil or a suitable plastic, and in some embodiments it is a container(for example, a pouch) made of oxygen-impermeable material. Suchcontainers include, for example, cans, jars, bottles, foil trays,plastic trays, foil pouches and plastic pouches. The containers may beflexible or rigid. A particularly preferred container is a plastic tray,advantageously used with a foil or plastic lid. The plastic may be asingle layer or, preferably a laminated material comprising areinforcing layer, such as a nylon or polyester layer, and a sealinglayer such as a polyethylene, polyvinylidene chloride or EVOH layer, forinstance nylon/polyethylene or polyester/polyethylene. Alternatively,the package can be a laminate of board and plastics material, such asthat sold as Combibloc. The advantage of packaging the pasta of theinvention in plastic materials is that the product can be reheated in amicrowave oven without the need to decant it before reheating.

In one embodiment, the pasta is packaged in the container under vacuumprior to pasteurization or other processing in connection with partialcooking (in which case the container is capable of withstanding heatingattendant to such pasteurization or other processing). In otherembodiments, the pasta of the present invention is preferably packed inthe container under an inert gas atmosphere, for example, to avoid anydiscoloration of the product by oxidation during pasteurization, otherprocessing, storage or display. Typically, the container is flushed withan inert gas, and then the container, is sealed and sterilized. Anysuitable, non-toxic inert gas can be used, but nitrogen and especiallycarbon dioxide or mixtures of nitrogen and carbon dioxide are preferred.Typically, the atmosphere within the container is substantially free ofoxygen. The package can be hermetically sealed.

Such packaging comprises substantially evacuating the container forholding the pasta, i.e., so that the air content in the container doesnot exceed 5%. In certain embodiments, pasteurization is effected byholding the pasta in the sealed container at a temperature of about 85°C., for example, about six minutes in steam for a pack 20 mm thick,followed by drying and cooling. When the pasta in the package is cool,reheating to the temperature mentioned above can be effected with steamor in hot water. Alternatively, the pasta may be pasteurized orotherwise processed in connection with partial cooking before thepackage is sealed.

The use of carbon dioxide is particularly advantageous in certainembodiments because it should provide further protection againstspoilage. For instance, if the pasta of the present invention issubjected to such conditions as would allow water to gather in thepackage, such water could provide a breeding ground for microorganisms.However, if the product is packed in a carbon dioxide atmosphere, thegas will dissolve in free water present. This makes the water a muchless conducive environment for growth of microorganisms. In otherembodiments, food grade diatomic nitrogen is advantageously employed. Bythis measure, CO₂ produced by spoilage microorganisms will not be maskedby CO₂ introduced as the inert atmosphere, and the detection of CO₂ willbe an indication of the presence of such microorganisms.

A further refinement of the invention comprises introducing raw orpartially cooked pasta into the container, typically but not necessarilydried to a moisture content of 12% or less, and a volume of a hotaqueous solution or suspension of the at least one polymericfood-acceptable acid. In one embodiment, the w/v ratio of pasta tosolution or suspension is such that the total fill weight of the productis 2.8 to 3.0 times the weight of dry pasta. The solution or suspensioncan advantageously be at an elevated temperature, such as from 82°-98°C., but this is not required in all cases. The solution or suspension isincorporated in an amount such that it can be completely, or at leastsubstantially, absorbed into the pasta upon heating. The container issealed and its contents heated under conditions suitable to effect suchabsorption, for example at 90°-100° C.

If desired, pasta of the present invention may be coated with a smallquantity of an edible oil, such as rice oil, sunflower oil, soybean oil,cottonseed oil or rape seed oil, for instance, to reduce sticking. Theedible oil is used in a sufficient amount to alter the mouthfeel of theproduct and to alter the tendency of the pasta to stick together orclump during prolonged storage. Typically, the edible oil comprises from0.5 to 1% by weight of the pasta. In one embodiment, the pasta may bepassed through a hot solution made from an emulsion of 50% water, 50%vegetable oil and emulsifiers, the emulsion being diluted tenfold withwater.

Further, if desired, the pasta can be quenched. It is preferred that thepasta be quenched, in an aqueous solution or suspension of at least onepolymeric food-acceptable acid as already described, after heating inconnection with precooking or partial cooking. A quenching liquid canalso advantageously contain one or more conventional acidulants (also asalready described) besides the polymeric acid. Whether or not aquenching liquid is used, the pasta can be washed (for instance inwater) between steps and separated from, e.g. drained of, all freeliquid prior to packaging or at least prior to sealing the container.

Accordingly, the finished precooked pasta in one embodiment of theinvention typically has a water content greater than 12% and a pH belowabout 4.6. Preferably, the pasta has a water content of about 65 toabout 75% and a pH from about 3.8 to 4.2. In particular, the pasta has apH of about 4.0. Additionally, the pasta typically contains acharacteristic acid component. This component preferably is included inan amount of approximately 0.2-2% (w/w), and especially 0.6% (w/w).

The acid component in the pasta includes any residue or moiety of theacid molecule which is present in the treated pasta and is a reflectionof the fact that the pasta has been treated. As described, the pasta ofthe invention has the full complement of advantages and features thatshould be demanded of a premium pasta product, namely (i) extended lifeat room temperature or normally prevailing refrigeration temperatures,(ii) ease of preparation and storage, (iii) freedom from the substantialpresence of ambient liquid in the stored condition, (iv) substantiallyno off-flavors when in a condition suitable for consumption, and (v)palatability and appearance comparable to, or better than, productsprepared from conventional dry pasta.

The present invention is further described and illustrated in thefollowing examples. It will be appreciated that these examples areprovided solely for the purposes of illustrating the invention and notfor the purpose of limitation. It will further be appreciated thatvariations and modifications to the product and process can be made bythe skilled person without departing from the spirit or scope of theinvention as defined in the appended claims.

EXAMPLE 1

Small spiral pasta prepared from a conventional pasta dough are used inthis example. A stock solution containing 10 grams alginic acid and 8.0grams citric acid in 4000 grams H₂ O and having a pH of 2.5 is prepared.

500 grams of the small spiral pasta is boiled in a stockpot for 12minutes in the stock solution. The cooked pasta is drained in a colanderand filled into gas-impermeable trays made of polypropylene or acombination of APET and CPET. Foil polylaminate lidding material isheat-sealed to the trays under pressure. The containers and theircontents are then placed in a retort, brought to an internal (center)temperature of 95° C. and held for 16 minutes to pasteurize the productThe product has a pH of 4.53; when reheated, the pasta has the sameorganoleptic properties as similar pasta cooked in a conventional mannerby boiling in water.

EXAMPLE 2

Small spiral pasta is prepared as in Example 1 except that rice oil isadded to the spirals before packaging in the amount of 3 g of oil per400 g of pasta. The product also has a pH of 4.53; when reheated, thepasta has the same organoleptic properties as similar pasta cooked in aconventional manner by boiling in water.

EXAMPLES 3-6

In these examples, stock solutions containing alginic acid and citricacid in water, in the amounts shown in the following table, areprepared. Pasta in the amounts shown is boiled in a stockpot for 15minutes in the stock solution. The cooked pasta is drained in a colanderand quenched in a stockpot with 2000 grams of the stock solution, andthen filled into gas-impermeable trays made of polypropylene. The traysare flushed with food grade nitrogen and sealed as described above.

    ______________________________________                                                        Amount    Amount                                                              citric    alginic Amount                                            Amount    acid      acid    water                                             Pasta     stock     stock   stock                                       Ex.   (grams)   (grams)   (grams) (grams)                                                                              pH                                   ______________________________________                                        3     250       4         4       2000   3.98                                 4     250       4         3       2000   4.00                                 5     312.5     5         5.14    2500   4.28                                 6     312.5     5         5.6     2500   4.41                                 ______________________________________                                    

In every case, when reheated, the pasta has the same organolepticproperties as similar pasta cooked in a conventional manner by boilingin water.

EXAMPLES 7-10

Pasta is prepared in these examples, in the amounts shown, in the sameway it is prepared in Examples 3-6 except that no quench solution isused.

    ______________________________________                                                        Amount    Amount                                                              citric    alginic Amount                                            Amount    acid      acid    water                                             Pasta     stock     stock   stock                                       Ex.   (grams)   (grams)   (grams) (grams)                                                                              pH                                   ______________________________________                                        3     250       4         4       2000   3.98                                 4     250       4         3       2000   4.00                                 5     312.5     5         5.14    2500   4.28                                 6     312.5     5         5.6     2500   4.41                                 ______________________________________                                    

Again, in every case, when reheated, the pasta has the same organolepticproperties as similar pasta cooked in a conventional manner by boilingin water.

EXAMPLES 11-16

In these examples, stock solutions containing alginic acid and/orpectinic acid in water, in the amounts shown in the following table, areprepared. Pasta in the amounts shown are boiled in a stockpot forminutes in the stock solution. The cooked pasta is drained in a colanderfor 1 minute and quenched in a stockpot with the stock solution. Allproducts are coated with vegetable oil.

    ______________________________________                                                        Amount    Amount                                                              pectinic  alginic Amount                                            Amount    acid      acid    water                                             Pasta     stock     stock   stock                                       Ex.   (grams)   (grams)   (grams) (grams)                                                                              pH                                   ______________________________________                                        11    500       15                4000   4.58                                 12    500       20                4000   4.32                                 13    500       10        10      4000   4.55                                 14    500       13        13      4000   4.35                                 15    500                 25      4000   4.52                                 16    500                 30      4000   4.50                                 ______________________________________                                    

Again, in every case, the pasta has the same organoleptic properties assimilar pasta cooked in a conventional manner by boiling water.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms or expressions of excluding any equivalents of thefeatures shown and described as portions thereof, its being recognizedthat various modifications are possible within the scope of theinvention.

We claim:
 1. A method for the preparation of an acid-stabilized pasta,which comprises contacting the pasta with an aqueous solution orsuspension of at least one polymeric food-acceptable acid in an amountsufficient to effect acid-stabilization such that said pasta has a pHbelow about 4.6 and substantial freedom from acid flavor notes, andwherein said pasta is shelf-stable.
 2. A method for the preparation ofacid-stabilized pasta, which comprises contacting the pasta with anaqueous solution or suspension of at least one polymeric food-acceptableacid in an amount, for a time, and at a temperature sufficient to effectthe pasta's acid-stabilization, wherein said pasta has a pH below about4.6 and its shelf-stable.
 3. A method as defined in claim 2, wherein thepolymeric food-acceptable acid is alginic acid.
 4. A method as definedin claim 2, which comprises cooking said pasta in the aqueous solutionor suspension of said polymeric food-acceptable acid.
 5. A method asdefined in claim 4, wherein said aqueous solution or suspension of atleast one polymeric food-acceptable acid has a pH from about 2.4 to 2.8.6. A method as defined in claim 4, wherein at least one otherfood-acceptable acid is dissolved or suspended in the aqueous solutionor suspension of at least one polymeric food-acceptable acid.
 7. Amethod as defined in claim 6, wherein each said other food-acceptableacid is selected from the group consisting of citric, malic, acetic,fumaric, tartaric, phosphoric, adipic, lactic, ascorbic, sorbic,propionic, erythorbic, sulfuric and hydrochloric acids.
 8. A method asdefined in claim 7, which comprises cooking said pasta in an aqueoussolution or suspension of at least one polymeric food-acceptable acidand of at least citric acid.
 9. A method as defined in claim 4, whichfurther comprises quenching said precooked pasta in an aqueous solutionor suspension of at least one polymeric food-acceptable acid.
 10. Amethod as defined in claim 9, wherein each polymeric food-acceptableacid used for quenching is alginic acid.
 11. A method as defined inclaim 9, wherein at least one other food-acceptable acid is dissolved orsuspended in the aqueous solution or suspension of at least onepolymeric food-acceptable acid used for quenching.
 12. A method asdefined in claim 11, wherein each said other food-acceptable aciddissolved or suspended in the aqueous solution or suspension used forquenching is selected from the group consisting of citric, malic,acetic, fumaric, tartaric, phosphoric, adipic, lactic, ascorbic, sorbic,propionic, erythorbic, sulfuric and hydrochloric acids.
 13. A method asdefined in claim 4, which comprises subjecting the pasta to processingconditions such that it is in an acid-pasteurized state.
 14. A method asdefined in claim 4, which comprises subjecting the pasta to processingconditions such that it is in a precooked state.
 15. A method as definedin claim 2, which comprises cooking pasta in an aqueous solution orsuspension of at least one polymeric food-acceptable acid underconditions such that said pasta has a pH from about 3.8 to 4.2.
 16. Amethod as defined in claim 15, which comprises cooking pasta underconditions such that said pasta has a pH of about 4.0.
 17. A method asdefined in claim 4, which further comprises separating said cooked pastafrom residual solution or suspension.
 18. A method as defined in claim4, which further comprises contacting said cooked pasta with an
 19. Amethod as defined in claim 18, wherein said amount of edible oil is fromabout 0.5 to 1% by weight of the pasta.
 20. A method for the preparationof shelf-stable pasta, which comprises cooking pasta in an aqueoussolution or suspension of at least one polymeric food-acceptable acidfor a time and at a temperature sufficient to effectacid-pasteurization, shelf-stability and a pH below about 4.6, andpackaging the pasta in a container.
 21. A method as defined in claim 20,which comprises subjecting the pasta to conditions such that the pastain the package is in a precooked state.
 22. A method as defined in claim20, wherein said packaging step comprises inserting a measured amount ofsaid precooked pasta into a container, flushing the container with aninert gas, sealing said container and sterilizing the contents thereof.23. A method as defined in claim 20, wherein said container ismicroorganism-impermeable, waterproof, or both microorganism-impermeableand waterproof.
 24. A method as defined in claim 20, wherein saidcontainer is a plastic tray or pouch.
 25. A method as defined in claim24, wherein said plastic tray or pouch comprises a laminate of areinforcing layer and a sealing layer.
 26. A method as defined in claim20, wherein said packaging step comprises substantially evacuating acontainer for holding the cooked pasta.
 27. A method for the preparationof shelf-stable pasta, which comprises introducing pasta into acontainer with an aqueous solution or suspension of at least onepolymeric food-acceptable acid in respective amounts such that the watercomponent of the solution or suspension can be substantially absorbedinto the pasta; sealing the container; and heating the contents of thecontainer such that the water component of the solution or suspension issubstantially absorbed into the pasta and such that acid-pasteurizationis effected and wherein a shelf-stable pasta is produced.
 28. A methodas defined in claim 27, wherein said pasta is partially cooked prior toits introduction into the container.
 29. A method as defined in claim27, which comprises subjecting the pasta to conditions such that it isin a precooked state upon completion of acid-pasteurization. 30.Acid-stabilized pasta prepared by the method which comprises contactingpasta with a polymeric food-acceptable acid under conditions such thatthe pasta is acid-stabilized without introducing acid-flavor notes,wherein said pasta has a pH below about 4.6 and is shelf-stable. 31.Acid-stabilized pasta as defined in claim 30, wherein said polymericfood-acceptable acid is alginic acid.
 32. Acid-stabilized pasta asdefined in claim 30, wherein said method comprises cooking said pasta inan aqueous solution or suspension of said polymeric food-acceptableacid.
 33. Acid-stabilized pasta as defined in claim 32, wherein saidaqueous solution or suspension of at least one polymeric food-acceptableacid has a pH from about 2.4 to 2.8.
 34. Acid-stabilized pasta asdefined in claim 32, wherein said acid is alginic acid 35.Acid-stabilized pasta as defined in claim 32, wherein at least one otherfood-acceptable acid is dissolved or suspended in the aqueous solutionor suspension of at least one polymeric food-acceptable acid. 36.Acid-stabilized pasta as defined in claim 32, wherein the pasta issubjected to conditions such that it is in an acid-pasteurized state.37. Acid-stabilized past as defined in claim 32, wherein the pasta issubjected to conditions such that it is in a precooked state. 38.Acid-stabilized pasta as defined in claim 33, wherein said cooking isunder conditions such that said pasta has a pH from about 3.8 to 4.2.39. Acid-stabilized pasta as defined in claim 38, wherein said cookingis under conditions such that said pasta has a pH of about 4.0. 40.Acid-stabilized pasta as defined in claim 30, wherein said pasta has awater content greater than 12%.
 41. Acid-stabilized pasta as defined inclaim 30, wherein the polymeric food-acceptable acid is selected fromthe group consisting of alginic acid, pectinic acid, carrageenic acidand carboxymethylcellulose acid.
 42. Acid-stabilized pasta as defined inclaim 36, wherein each said other food-acceptable acid component isselected from the group consisting of citric, malic, acetic, fumaric,tartaric, phosphoric, adipic, lactic, ascorbic, sorbic, propionic,erythorbic, sulfuric and hydrochloric acids.
 43. Acid-stabilized pastaas defined in claim 35, wherein said other food-acceptable acidcomponent is citric acid.
 44. Acid-stabilized pasta as defined in claim40, which further comprises an amount of edible oil sufficient toprevent the pasta from sticking together.
 45. Acid-stabilized pasta asdefined in claim 44, wherein said amount of edible oil is from about 0.5to 1% by weight of the pasta.
 46. A system which comprisesacid-stabilized pasta as claimed in claim 40, and a container in whichthe pasta resides.
 47. A system as defined in claim 46, wherein saidcontainer is microorganism-impermeable, waterproof, or bothmicroorganism- impermeable and waterproof.
 48. A system as defined inclaim 46, wherein said container is a plastic tray or pouch.
 49. Asystem as defined in claim 66, wherein said plastic pouch comprises alaminate of a reinforcing layer and a sealing layer.
 50. A system asdefined in claim 46, wherein the pasta is under vacuum within thecontainer.
 51. A system as defined in claim 46, wherein the pastaresides in an inert atmosphere within the container.
 52. Anacid-stabilized pasta prepared by acidifying pasta with an aqueoussolution or suspension of at least one polymeric food-acceptable acid ina quantity sufficient to provide pasta having a pH below about 4.6. 53.An acid-stabilized pasta as defined in claim 52, wherein said aqueoussolution or suspension of at least one polymeric food-acceptable acid ispresent in the pasta dough.
 54. An acid-stabilized pasta as defined inclaim 52, further prepared by heat-pasteurizing the pasta.
 55. Anacid-stabilized pasta as defined in claim 53, further prepared byheat-pasteurizing the pasta.
 56. A method for the preparation ofacid-stabilized pasta, which comprises introducing said polymericfood-acceptable acid during formulation of the pasta dough.
 57. A methodas defined in claim 56, further comprising heat-pasteurizing the pasta.58. A method of preparing pasta for consumption, which comprises heatinga product as defined in claim
 30. 59. A method as defined in claim 1,wherein the polymeric food-acceptable acid is a non-alginic polymericfood-acceptable acid.
 60. A method as defined in claim 59, whichcomprises cooking said pasta in an aqueous solution or suspension of atleast one non-alginic polymeric food-acceptable acid and of at leastcitric acid.
 61. A method as defined in claim 1, wherein the at leastone polymeric food-acceptable acid has a pH of less than 3.0 or greaterthan 4.0 and less than or equal to 6.0.
 62. A method for the preparationof shelf-stable pasta, which comprises introducing pasta into acontainer with an aqueous solution or suspension of at least onepolymeric food-acceptable acid having a pH of less than 3.0 or greaterthan 4.0 and less than or equal to 6.0, in respective amounts such thatthe water component of the solution or suspension can be substantiallyabsorbed into the pasta, said container being capable of maintaining thepasta throughout the period of its shelf-stability; sealing thecontainer; and heating the contents of the container such that the watercomponent of the solution or suspension is substantially absorbed intothe pasta and such that acid-pasteurization is effected. 63.Acid-stabilized pasta produced by the method defined in claim 59, 60, 61or 62.